Lightweight bowling ball



Al1g 9, v1966 c. o. DEGNER ETAL 3,265,392

LIGHTWEIGHT BOWLING BALL original Filed March 27, 196s United States Patent O LIGHTWEGHT BOWLING BALL Carl 0. Degner, Muskegon, Fred E. Satchell, Grand Haven, and Edward W. Gatiield, Muskegon, Mich. assgnors to Brunswick Corporation, a corporation of Delaware Original application Mar. 27, 1963, Ser. No. 268,261. Divided and this application .lune 15, 1965, Ser. No. 483,900

Claims. (Cl. 273-63) This application is la divisional lapplication of copending application, Serial No. 268,261, entitled Bowling Ball, and filed March 27, 1963, now abandoned.

This invention relates to bowling balls and more particularly to new and useful bowling balls having lightweight cores.

It is common practice for a bowling ball manufacturer to provide bowling balls of Ia variety of different weights, e.g. for use by men and women. In the manufacture of the heavier weight bowling balls, higher density, structurally sound and impact resistant materials yare readily available and may be conveniently used. However, where it is deired to provide lighter weight bowling balls a real problem exists -in obtaining economical lightweight materials with suicient inherent struc-tural properties and inherent impact resistance properties, to serve as bowling ball materials and especially `as materials of construction of bowling ball cores.

It has been discovered that where a lightweight or low density material is enclosed in a rigid outer layer of material as a part of a bowling ball core, its structural properties, and especially its impact resistance, may be improved suiciently .to render usable in bowling ball applications even those materials which possess lpoor impact resistance. Such materials can be used as bowling ball core members even in the absence of extremely rigid enclosing members such as rigid metal enclosing support members. The low density material itself becomes capable `of receiving a greater amount of impact and can actually function as a structural support inem-ber 'for rigid outer ball layers which ilex sufficiently under impact to transmit at least a portion of the impact forces inwardly to the low density material.

A general object lof this invention is to provide a new and useful bowling ball as herein disclosed or exemplified.

Another object of this invention is to provide a bowling ball having an outer cover and an inner core which includes a mass of low density material enclosed within the bowling ball as at least a part of the core.

Still another objects is to provide a bowling ball which has an exterior hard cover and an inner solid core of balsa Wood.

It is a further object of this invention to provide a bowling ball having a generally spherical c-ore of laminated balsa wood laid up with end grains on .the spherical surface of the core and with a cover enclosing the spherical core and supported by the spherical core.

It is yet another object of :this invention to provide a bowling ball in accordance with the lforegoing obje-cts wherein the mass of low density structural material, such as balsa wood, is enclosed by an outer core member and the outer core member is in turn enclosed by the bowling ball cover.

It is la still further object of this invention to provide a bowling ball having 'a low density core land a transparent cover such `as a transparent polyester cover which permits viewing ofz the core outer surface from the exterior of the ball.

Yet another object of this invention is Ito provide a bowling ball having a solid core in accordance with the foregoing objects wherein the low density material norice mally possesses poor impact resistance, but, in its enclosed condition within the bowling ball, is improved in impact resistance.

Additional objects will be apparent to those in the art from the following descriptions and from the drawing in which: V

FIGURE 1 is a section through an embodiment of -a bowling ball of this invention; and

FIGURE 2 is a -section through another embodiment of a bowling ball of this invention.

While this invention is susceptible of embodiment in many different forms, there is shown in the drawing, and will herein be described in detail embodiments of the invention with the understanding that the present disclosure is to be considered las an exemplication of the principles of the invention land is not intended to limit fthe invention to the embodiments illustrated.

In FIGURE 1 there is illustrated an embodiment of the present invention which includes a low density centrally located inner core 11 of laminated balsa wood blocks which constitutes the inner core of the bowling ball. Sur-rounding inner core 11 is an outer rigid core 12 which is composed of sawdust bonded together with Ia rigid polyester resin such as that formed by curing the following composition:

Rigid polyester resin: Percent by weight Butylene glycol 21 Diethylene glycol 23.3 Isophthalic acid 37.9 Furnaric acid 17.66 Triphenyl phosphite .1 Hydroquinone .2

dissolved or dispersed in styrene or vinyl toluene in a ratio of 35% resin to 65% styrene vor vinyl toluene.

Surrounding outer core 12 is `a cover material 13 such as black rubber vulcanized in place over the outer core.

Turning now to FIGURE 2, there is illustrated a bowling ball which is composed of a low density core 21 of balsa wood and a transparent cover 23 surrounding core 21. The balsa wood core is a spherical mass of laminated pieces of balsa wood oriented so that the end grains `of the bals-a wood fall upon the spherical surface of the core. Cover 23 is a thermoset transparent polyester cover cured in Situ. The polyester resin from which the cover is prepared is a 4reaction product of the acids and alcohols indicated in the molar proportions shown in the following formulation dissolved in 40% styrene Iand containing 0.2% hydr-oquinone inhibitor:

Component: Mols Propylene glycol 7 Diethylene glycol 4 Furnaric acid 3 Phthalic anhydride 4 Adipic acid 3 Preferably the mass of low density material is a spherical mass which is centrally positioned in the bowling ball. The mass is contained by yan outer portion of the bowling ball to improve its impact resistance.

As is seen with reference to the drawings, the mass of low density material may be immediately surrounded by the bowling tball cover (FIGURE 2) or may be surrounded by an outer core member which is in turn surrounded by `the bowling ball cover (FIGURE l). The low density material provides a lightweight core `of good impact resistance in its enclosed position or form within the bowling ball. The mass functions as a support structure for .an outer phase of core 'and/or for the cover material. The low `density material `also proportions the weight of the bowling ball to provide a greater proportion of the total bowling ball weight closer to the bowling ball surface. Additionally, the low density mass surprisingly adds a remarkable degree of impact resistance land obviates the use of exceedingly rigid materials, such as metals, in one of the outer phases as may be required where the central portion of the ball is void, in order to produce a ball capable of withstanding normal bowling impacts.

The low density mass may advantageously be a block or a plurality of laminated blocks of low density woods such as those h-aving a density of 'about 0.4 gm./cc. or less, including, ibut not necessarily limited to, balsa, white cedar, western red cedar, balsam fir, balsam poplar, corkwood, `butternut, aspen and the like. The especially preferred low density core material is balsa, because of its very low density.

The @advantageous use of balsa wood is best illustrated in FIGURE 2. The structure takes advantage of the greater impact resistsance of balsa wood against the end grains by orientation of the laminated blocks of balsa, of which the core is composed, to provide bal-sa end grains -on or defining the spherical surface of the core. Such orientation of the end grains of balsa is especially useful where less outer enclosing structure or cover material is used in the ball. A b-all of very light weight may thereby be provided.

In laddition to the woods, `and especially balsa wood, other low density materials may be used to form the core of a bowling ball in accordance herewith. Such other materials particularly include the foamed plastics, such as fo-amed polystyrene and urethane foams.

The cover materials for the present bowling balls may be any of the usual cover materials which may be applied in conventional manner in their usual thicknesses. If the low density mass of -material used in the core is damaged by impact in testing of the ball, a thicker cover member or a layer of outer core may be used. Thus, the low density core mass is enclosed by suicient rigid material to render its impact resistance sufficiently high to resist the impacts received in bowling games. EX- amples of Isuitable cover materials include rubber, polyester resins, alkyd resins, acrylic resins, epoxy resins, other synthetic resins and the like. Such cover miaterials `are well known to those in the art.

In one embodiment, where it is desired to include core design in the outer appearance of the Iball, a transparent or translucent cover material is highly desirable.

However, in any event, the preferred cover materials 4are the polyester resins such as those prepared by polyesterification of polycarboxylic acids such as succinic, maleic, fumarie, sebacic, phthalic, etc., acids with such polyhydroxy compounds as ethylene glycol, propylene glycol, butane 2,3-diol, etc. The cover resins can be modiiied with other resins, as well as fillers or inhibitors, as is Well known in the art. Usual-1y the resinsare thermosetting and m-ay advantageously include such additional monomers las the monethylenically unsaturated monomers including styrene, methyl methacrylate, butyl acrylate, alphamethyl styrene, and the like.

Where it is desired to use an outer core between the inner low density core and the cover material, such outer core may be composed of any of the normal core materials conventionally used as structural impact resistant cores in bowling balls. Such cores are usually made of sawdust, cork, residual cover stock, microhalloons, or the like, bonded together by a thermoset resin, such as a polyester resin or simi-lar epoxy, urea, or phenolic resin or by a thermoplastic material such as polystyrene. The core material may be molded in place surrounding the inner low density mass in a manner similar t-o molding a resin cover in situ on a bow-ling lball core. Such molding techniques are well known tothose in CII the art and do not form a part of this invention. The core material is cured in situ and, in order to decrease curing time, .a small 'amount of curing catalyst may be used. For example, benzoyl peroxide may be used as a catalyst for a polyester resin bonding material.

The weight of the core land the cover, including the weight of the inner core and outer core members where two such core members lare present, can be varied and the materials used can be preselected with respect to their density for the purpose of manufacturing a bowling ball, and especially a llightweight bowling ball, having a predetermined weight. Bowling balls having the same or different weights may conveniently be constructed.

In view of the low density core material used in accordance herewith, it is apparent that very lightweight 'bowling balls may be constructed.

yIt is an advantageous feature of the invention that a greater proportion of the weight of the Ibowl-ing ball is distributed closer to the bowling ball surface. Such distribution provides greater rotational momentum in a rolling ball, ya feature which may often be desirable, especially in light balls, for example. It is evident that use of balsa wood, having a density of about 0.2 gm./cc., as a core material in lieu of a conventional core material having a density of about 0.6 gm./cc., in a covered ball wherein the cover material has -a density o-f about 1.2 gm./cc. will dispose a greater proportion of the total weight of the ball toward the surface to increase rotational momentum.

We claim:

1. A bowling ball comprising a generally spherical core of laminated balsa wood laid up with end grains defining the generally spherical surface and a-n exterior hard cover supported by said spherical Core and having a smooth outer rolling surface, said cover enclosing said core and said enclosed core being impact resistant.

2. A bowling ball comprising a generally spherical balsa wood core having end grains oriented to define the spherical surface thereof and a transparent polyester cov-er surrounding said core and having a smooth, spherical outer surface.

3. A bowling ball comprising an outer cover with a spherical, smooth outer surface and an inner solid core including a central spherical structural mass of laminated balsa wood laid up with end grains oriented to define the outer surface of said mass enclosed within said bowling ball and having improved impact resistance thereby imparted thereto, said balsa wood having a density no ygreater than about 0.4 gm./cc.

4. The bowling ball of claim 3 wherein said outer cover is supported by said spherical mass in direct contact with the spherical surface of said spherical mass.

5. The bowling ball of claim 3 wherein said outer cover is a `transparent polyester cover.

References Cited by the Examiner UNITED STATES PATENTS 1,504,461 8/1924 Whelan 273--63 1,518,130 12/1924 Barach r273---63 1,620,310 3/1927 Whelan '273- 82 1,622,421 3/1927 Coield 273--58 X 2,291,738 8/1942 Luth et al 273-63 2,364,955 12/1944 Diddel 273--230 2,467,043 4/ 1949 Kotler 273--128 2,618,481 11/1952 Dosker 273-82 3,034,791 5/1962 Gallagher.

3,068,007 12/1962 Satchell.

3,090,620 5/1963 Con-solloy 273-63 DELBERT B. Lows, Primm Examiner.

G. .T MARLO, Assistant Examiner. 

1. A BLOWING BALL COMPRISING A GENERALLY SPHERICAL OF LAMINATED BALSA WOOD LAID UP WITH END GRAINS DEFINING THE GENERALLY SPHERICAL SURFACE AND AN EXTERIOR HARD COVER SUPPORTED BY SAID SPHERICAL CORE AND HAVING A 